Me and a buddy has the Orgen 450 gps. Some other friends has some older orgen gps's. When we go trail riding, we carry all of them in our saddle bags, our two 450's records same amount of miles together, but our friends older units records something different, but they are the same together also. We've both checked the units with our trucks, all seemed to work correctly. Any body experienced this? Thanks for replys!